This paper studied the dynamics of a heavy quark moving through a strongly coupled plasma with broken conformal symmetry using the gauge/gravity duality.
We considered a holographic five-dimensional model consisting of Einstein gravity coupled to a scalar field with a non-trivial potential corresponding to a dual four-dimensional non-conformal gauge theory that exhibits a renormalization group flow between two different types of fixed points (located at UV and IR) at zero temperature [1]}. The parameter \(\phi _M\)  indicates the deviation from conformality, as shown in Fig. REF . According to the AdS/CFT dictionary, the heavy quark is associated with a string attached to the boundary of the AdS space. The string equation of motion was solved numerically for different values of parameter \(\phi _M\) , and then the drag force was computed by obtaining the corresponding conjugate momenta. Our results indicate that the drag force in this non-conformal plasma is smaller than \(\mathcal {N} = 4\)  super-Yang-Mills plasma. By increasing the level of non-conformality (the value of parameter \(\phi _M\) ), the drag force decreases, see Fig. REF . The ratio of drag force to its conformal limit reaches one at high temperatures. At finite temperature, this ratio is smaller than one for different values of \(\phi _M\)  but increases slowly by increasing the velocity of quark, see Fig. REF .
